Duration of positive urine for cocaine metabolite after ophthalmic administration: implications for testing patients with suspected Horner syndrome using ophthalmic cocaine

Horner Syndrome: A Clinical Review

Horner syndrome results from an interruption of the oculosympathetic pathway. Patients with Horner syndrome present with a slightly droopy upper lid and a smaller pupil on the affected side; less commonly, there is a deficiency of sweating over the brow or face on the affected side. This condition does not usually cause vision problems or other significant symptoms, but is important as a warning sign that the oculosympathetic pathway has been interrupted, potentially with serious and even life-threatening processes. The oculosympathetic pathway has a long and circuitous course, beginning in the brain and traveling down the spinal cord to exit in the chest, then up the neck and into the orbit. Therefore, this syndrome with unimpressive clinical findings and insignificant symptoms may be a sign of serious pathology in the head, chest, or neck. This clinical review discusses how to identify the signs, confirm the diagnosis, and evaluate the many causes of Horner syndrome.

Clinical Interpretation of Urine Drug Tests: What Clinicians Need to Know About Urine Drug Screens

Urine drug testing is frequently used in clinical, employment, educational, and legal settings and misinterpretation of test results can result in significant adverse consequences for the individual who is being tested. Advances in drug testing technology combined with a rise in the number of novel misused substances present challenges to clinicians to appropriately interpret urine drug test results. Authors searched PubMed and Google Scholar to identify published literature written in English between 1946 and 2016, using urine drug test, screen, false-positive, false-negative, abuse, and individual drugs of abuse as key words. Cited references were also used to identify the relevant literature. In this report, we review technical information related to detection methods of urine drug tests that are commonly used and provide an overview of false-positive/false-negative data for commonly misused substances in the following categories: cannabinoids, central nervous system (CNS) depressants, CNS stimulants, hallucinogens, designer drugs, and herbal drugs of abuse. We also present brief discussions of alcohol and tricyclic antidepressants as related to urine drug tests, for completeness. The goal of this review was to provide a useful tool for clinicians when interpreting urine drug test results and making appropriate clinical decisions on the basis of the information presented.

Horner syndrome: clinical perspectives

Horner syndrome consists of unilateral ptosis, an ipsilateral miotic but normally reactive pupil, and in some cases, ipsilateral facial anhidrosis, all resulting from damage to the ipsilateral oculosympathetic pathway. Herein, we review the clinical signs and symptoms that can aid in the diagnosis and localization of a Horner syndrome as well as the causes of the condition. We emphasize that pharmacologic testing can confirm its presence and direct further testing and management.

Disorders of the pupil

Pupil size is determined by the interaction of the parasympathetic and the sympathetic nervous system. The parasympathetic system conducts the light reaction with its major center in the dorsal midbrain. The sympathetic nervous system acts either directly on the dilator muscle (peripherally) or centrally by inhibiting the Edinger-Westphal nucleus. Psychosensory reactions are transmitted via the sympathetic system. The afferent input of the light reflex system in humans is characteristically wired, allowing a detailed analysis of a lesion of the afferent input. Even in humans a subgroup of ganglion cells containing melansopsin plays an important role as a light sensor for the pupillary system. To diagnose normal pupillary function, pupils need to be isocoric and react bilaterally equally to light. Anisocoria indicates a problem of the efferent pupillary pathway. Pupillary disorders may involve the afferent pathways (relative afferent pupillary defect) or the efferent pathways. Physiological anisocoria is a harmless condition that has to be distinguished from Horner's syndrome. In this case pharmacological testing with cocaine eye-drops is helpful. Disorders of the parasympathetic system will impair the light response. They include dorsal midbrain syndrome, third-nerve palsy, and tonic pupil. Tonic pupils are mainly idiopathic and do not need imaging. Disorders of the iris, including application of cholinergic agents, need also to be considered in impaired pupillary light reaction.

Horner syndrome

Horner syndrome refers to the constellation of signs resulting from the interruption of sympathetic innervation to the eye and ocular adnexae. Classically, the clinical findings include a triad of ipsilateral blepharoptosis, pupillary miosis, and facial anhidrosis. The history, additional clinical examination features, and pharmacologic testing may help localize the lesion and suggest an etiology. An appropriate evaluation of Horner syndrome and a timely elucidation of the etiology may allow for a potentially life-saving intervention.